Myth Busted–speed kills? The best rate for good presentations

By Christian Lundberg

One of the most hallowed pieces of advice that public speaking and presentation consultants give their clients is to slow down. The advice makes intuitive sense: when you are speaking in a high-stakes situation, you are likely to be a bit nervous, and when we are a bit nervous, we tend to speak more quickly. So, the conventional wisdom goes, you should slow down to make it easy for your audience to follow you.

Data suggests otherwise. The average conversation in English runs around 110 to 150 words per minute. Some of that range is based on regional differences and some of that range is based on personal differences. What is interesting is that audiences have a much greater capacity than we might expect to listen to high rates of speed.

Work as far back as the 1960’s established that whether a speaker was speaking at a plodding 100 wpm or 400 wpm, comprehension of the material did not change significantly (Voor and Miller, 1965) . Recent work in neuroscience has demonstrated that speech remains comprehensible at rates much higher than 150 words per minute. In one experiment (Peelle & McMillan et. al. Brain and Language, 91 (2004): 315-325) researchers compressed speech fragments to 50% of their original length by taking out the pauses between words in conversational speech. They found that even at this admittedly frenetic rate, comprehension did not change significantly. When the same researchers conducted fMRI imaging on listeners’ “brains on speed,” they found that higher rates of speed in speech forced listeners’ brains to compensate by recruiting more areas to process speech. But the recruitment of more areas of the listeners’ had a surprising side effect: it increased listeners’ attention and made them more prone to goal-oriented behavior (convenient side effects if you want to persuade an audience!).

But, some might say, just because an audience can follow you does not mean that it is aesthetically pleasing to listen to a quick speaker. Not so fast, say the data. In one study, social psychologist Norman Miller and his colleagues found that “fast talkers” (those speaking at about 200 words per minute) tended to be perceived by audiences as more persuasive, more credible, more objective, and more intelligent. Two researchers from the University of Georgia (Smith and Shaffer) found that fast talking was especially effective when the message ran counter to the listener’s attitudes: an intermediate rate was less effective, and a slow rate was the least effective of all.

Anecdotal evidence supports the insights of these studies in communication, social psychology and neuroscience when it comes to speed. Some of the most persuasive speakers in american public addresss delivered speeches that hit blistering speeds. John F. Kennedy holds the world record for words per minute in a public speech, hitting 327 words per minute. Martin Luther King was measured at over 300 words per minute at points.

Does this mean that you should aim for a uniformly rapid fire rate of delivery? Far from it. Kennedy also had a number of stretches (including famously in his inaugural speech) where he spoke under 100 words a minute.

So what is a speaker to do? Well, you don’t have to focus on slowing down: focus on using speed to your advantage by pacing your speech with intention. The keys to speaking well at any rate of speed require you to focus on: articulation of individual words, planning points of emphasis that highlight important content with changes in tone and or volume, utilizing effective pauses, and most crucially varying your rate of speed. The best evidence on persuasive speaking available to us today says that it is not rate (or tone, or volume for that matter) in the abstract that matters, but rather that a speaker modulates their speed to signal their intended emotional state or “verbally underline” their content. When you are addressing a matter of grave importance, you should turn the rate down–and when you are signaling passion or excitement for an idea, turn the rate up a bit.

But whatever you do, don’t plod or aim to speak “just below your conversational rate.” A good speech, full of intentional pauses, variations in rate, volume, and tone, may well clock in above conversational rate in the aggregate, or in absolute terms: but if you use vary your speed with intention, and if you match your rate (and style) of delivery to your material, your audience will reward your efforts.